The Department for Education last night defended its flagship programme for improving inner-city schools after an Ofsted study questioned its impact on raising standards.

The government has spent £800m on the Excellent in Cities programme (EiC) since it was launched by Tony Blair in 1999.

But Ofsted inspectors are reported to have found few signs that the programme has achieved its aim of improving standards in city schools "higher and faster than elsewhere".

A leaked copy of the inspectors' report, which is due to be published next week, concludes that although there have been some benefits "the impact on the programme of achievement is more variable".

But the inspectors found that the programme had improved the behaviour of difficult pupils, reducing expulsions and cutting truancy in schools with social problems, according to the Times.

Improved classroom standards were evident among primary school pupils but were much less evident among older children at secondary schools.

Last night the Department for Education insisted the standards areas covered by the programme had improved faster than elsewhere in the country.

"They have improved most in areas where they have had EiC for longest," a spokeswoman said.

"In inner London, Birmingham, Liverpool and Leeds GCSE standards have improved at almost double the rate for the rest of the country."

Early independent research had indicated that the EiC schools were improving faster than in those not covered by the programme.

Damian Green, the Conservative education spokesman, said funding from the programme should be diverted to protect teachers' jobs amid reports that schools might have to make 5,000 staff redundant. "This looks like another expensive flagship programme that isn't working," he said.

"These glossy government initiatives do much less good than giving the heads the money they need to get on with the job."

The Ofsted report is to be launched by David Bell, the chief inspector of schools in England. The EiC programme first ran in six areas but has been expanded to cover 58 local authorities, with more than 1,000 primary schools.

David Miliband, the school standards minister, said last October: "The figures showing the EiC areas have had four times improvement in maths GCSE results than the national average are very striking.

"Heads and teachers are universally positive - it has brought them together to share good practice."

Schools covered by the EiC programme receive additional funding to provide learning mentors, extra tuition for "gifted and talented" pupils, and support so that the most disruptive pupils can be taught separately.